Heart valve disease is a widespread condition in which one or more of the valves of the heart fails to function properly. Diseased heart valves may be categorized as either stenotic, wherein the valve does not open sufficiently to allow adequate forward flow of blood through the valve, or incompetent, wherein the valve does not close completely, causing excessive backward flow of blood through the valve when the valve is closed. A heart valve may also be both stenotic and incompetent. Valve disease can be severely debilitating and even fatal if left untreated, particularly if the diseased valve is the mitral valve (between the left atrium and left ventricle) or the aortic valve (between the left ventricle and the aorta). According to recent estimates, more than 80,000 patients are diagnosed with aortic or mitral valve disease in U.S. hospitals each year. Recent statistics show that valvular heart disease is responsible for nearly 20,000 deaths each year in the United States, and is a contributing factor in approximately 42,000 deaths. Currently, the primary treatments of valve disease are valve repair and valve replacement. Worldwide, there are approximately 300,000 heart valve replacement surgeries performed annually.
A number of interventional approaches have been developed for treating heart valve disease. For instance, annuloplasty rings have been developed in various shapes and configurations over the years to correct mitral regurgitation and other conditions which reduce the functioning of the valve. Heart valve replacement may be indicated when there is a narrowing of a native heart valve, commonly referred to as stenosis, or when the native valve leaks or regurgitates, such as when the leaflets are calcified. When replacing the valve, the native valve may be excised and replaced with either a biologic or a mechanical valve.
Annuloplasty rings are useful in treating some diseased valves where valve function can be restored by reshaping the valve annulus. In an annuloplasty procedure, the effective size of the valve annulus is contracted, and/or the valve annulus is otherwise reshaped, by attaching a prosthetic annuloplasty ring to an interior wall of the heart around the valve annulus. The annuloplasty ring may comprise an inner substrate of a metal such as stainless or titanium, and/or a flexible material such as silicone rubber or Dacron cordage, covered with a biocompatible fabric or cloth to allow the ring to be sutured to the heart tissue. The annuloplasty ring may be stiff or flexible, may be split or continuous, and may have a variety of shapes, including circular, D-shaped, C-shaped, or kidney-shaped. Examples are seen in U.S. Pat. Nos. 4,917,698, 5,061,277, 5,290,300, 5,350,420, 5,104,407, 5,064,431, 5,201,880, and 5,041,130, which are incorporated herein by reference.
Using current techniques, most valve repair and replacement procedures require a gross thoracotomy, usually in the form of a median sternotomy, to gain access into the patient's thoracic cavity. A saw or other cutting instrument is used to cut the sternum longitudinally, allowing two opposing halves of the anterior or ventral portion of the rib cage to be spread apart. A large opening into the thoracic cavity is thus created, through which the surgical team may directly visualize and operate upon the heart and other thoracic contents. Alternatively, a thoracotomy may be performed on a lateral side of the chest, wherein a large incision is made generally parallel to the ribs, and the ribs are spread apart and/or removed in the region of the incision to create a large enough opening to facilitate the surgery.
Using such open-chest techniques, the large opening provided by a median sternotomy or thoracotomy can enable the surgeon to see the diseased valve directly, and to position his or her hands within the thoracic cavity in close proximity to the exterior of the heart for cannulation of the aorta and/or coronary arteries to induce cardioplegia, manipulation of surgical instruments, removal of excised tissue, and introduction of an annuloplasty ring or a replacement valve for attachment within the heart. Most interventional techniques are conducted under general anesthesia and require that the patient's sternum be opened and the chest be spread apart to provide access to the heart. The first 2-3 days following surgery are often spent in an intensive care unit where heart functions can be closely monitored. The average hospital stay is between 1 to 2 weeks, with several more weeks to months required for complete recovery. While often very effective, the use of open-heart surgery to perform cardiac procedures may be highly traumatic to the patient.
While heart valve surgery produces beneficial results for many patients, numerous others who might benefit from such surgery are unable or unwilling to undergo the trauma and risks associated with open-chest procedures. Recently, minimally invasive surgical techniques and procedures to perform traditionally open-chest cardiac surgical procedures are gaining acceptance. A wide variety of laparoscopic, arthroscopic, endovascular, and other surgical therapies have been developed. These procedures generally utilize trocars, cannulas, catheters, or other tubular sheaths to provide an artificial lumen through which specialized tools are inserted and manipulated by the surgeon. Such minimally-invasive procedures substitute one or more relatively small port holes or other intercostals incisions through the patient's chest wall for the larger sternotomy and thoracotomy approach of conventional open-chest surgeries. A major advantage of such minimally-invasive approaches is that the procedure avoids cutting through bones or other hard tissues of the patient, instead cutting incisions only into soft tissue. Such soft tissues typically heal much faster than bones, and with less discomfort to the patient.
Annuloplasty rings and even many prosthetic valves are usually relatively small, but even their relatively small sizes can still be a challenge for introduction into and manipulation/positioning within a patient's chest cavity, particularly where it is desirable to introduce the devices into a patient via intercostal incisions in order to avoid cutting through bone. Typical intercostal incisions have widths of about 20 mm and lengths of about 30 mm. While the large length of many intercostals space may permit the length of an intercostal incision to be extended beyond 30 mm, the width of intercostal spaces prevent the creation of intercostal opening with widths beyond about 20 mm Greater intercostal opening widths may require cutting into adjacent ribs and/or displacing adjacent ribs to the point where the bones are cracked and/or bruised by the displacement, which can increase the risk of trauma to the patient as well as extend recovery time. Accordingly, devices and handles that can be introduced through an opening of about 20 mm width may be desirable for minimally invasive procedures via intercostals incisions.
Annuloplasty ring prostheses are generally mounted on a holder assembly to facilitate their manipulation during the course of a surgical intervention and their implantation. Current holder assemblies are characterized by a number of drawbacks. A great majority of holders are configured with a rigid handle and a fixed orientation of the holder body or prosthesis carrier relative to the handle. Such a mechanical limitation does not allow the surgeon to orient the holder body relative to the handle in order to optimize the delivery of the prosthesis to the implant site. Some holder assemblies have been configured with malleable handles in an attempt to alleviate this drawback. However, such malleable handles are generally difficult to reshape in different bent configurations once they have been initially bent.
In view of actual and perceived drawbacks associated with current annuloplasty and prosthetic valve deployment techniques, there is a need for a less invasive approach and improved handle. The current invention satisfies these needs.